27 days ago, this 34-pound strip loin of beef went into a climate-controlled dry-aging room. 650 hours and millions of chemical reactions later, a visionary, flavor-chasing chef will slice away its moldy exterior to yield the most amazing $50 strip steak you’ll ever eat at Gotham Bar and Grill, NYC

Dry-Aged Beef Is a New Trend in Restaurants Around the Country

First comes the fat, like butter’s big brother, sent out with your bread. Then comes a broth made from the bones, so rich it coats your throat, leaving the tiniest bite of salt at the back. Finally, several courses later, there are actual slices of rib eye, some rare and tender, some cooked crisp. The meat has an indelible flavor. It plays hide-and-seek–here a flash of woody musk, there a hum of sweetness, and then: cheese, ripe cheese. Alongside, there is a maitake, the meatiest of mushrooms, charred in beef fat, and a jus so dark it’s borderline evil. It’s a poem of a steakhouse.

Except you’re not at a steakhouse. This is how Daniel Humm does steak at Eleven Madison Park, the ambitious tasting menu-only spot in New York City. For chefs like Humm who idealize culinary creativity, steak has traditionally been the most snoozy thing on a menu, a relic of the days before diners expected kitchens to lead them into uncharted waters. The problem with reinventing steak is that when people order a slab of beef, what they want is a slab of beef, charred, medium-rare. So instead of fighting this, Humm and others like him are finding inspiration in the beef itself–and making the experience new by making the meat very, very old.

All those flavors in the fat, the broth, and the steak–the sweetness, the nuttiness, the bite, the cheesy funk–are the result of dry-aging. Just as the food world became obsessed with cured meats in the last decade, trendsetting restaurants are turning to old ways of handling fresh beef: hanging it and letting time and microbes do their magic. Until recently, the only people who still dry-aged beef were grizzled butchers and operators of dark-paneled steakhouses, and even then they only let it go for a civilized 21 or 28 days. (For one reason, it’s expensive, an accountant’s nightmare, really: You tie up your cash in inventory that’s just sitting around, losing water weight and literally shrinking.) But lately there’s been a funktastic arms race among chefs in search of new flavors through longer aging times: 35, 42, 56 days. Saison, in San Francisco, regularly takes its beef out to 90; Eleven Madison Park, 140; and, in the sun-addled haze of Las Vegas, Mario Batali’s Carnevino features steaks so old they’re verging on toddlerhood. (Nicole Brisson, the chef at Carnevino, describes her eight-month-old, $100-per-inch riserva steaks as having deep flavors of Gorgonzola and truffles, the edible equivalent of a story that always ends with “I guess you had to be there.”)

“Lately, there’s been a funktastic arms race among chefs in search of new flavors through longer aging times: 35, 42, 56 days.”

I sit with Humm in the dining room of his restaurant, an airy Art Deco vault with 25-foot-tall windows bathing us in spring light, and talk about dank meat lockers and dark, shriveled meat. Growing up in Switzerland, Humm had never heard of dry-aged beef. Now he’s preaching with the zeal of the converted. “Discovering dry-aged beef was life-changing,” he says. “It smells so good. It’s got a smell like a truffle has a smell. It almost gets you high.”

We go into the kitchen. “Here: I love this,” says Humm, putting his nose to a rib rack that is at least five different colors: maize-y fat, black-brown crust, snowy patches of mold, creamy bone, and deep-red meat. It smells like wet earth and cheeseburgers. “The outside gets so hard you have to break into it, like a mountain cheese. But then the meat underneath reveals itself, and it’s red and beautiful. It’s amazing.”

The dramatic effects of dry-aging are the result of more than making meat do time in a cooler. I’ve had eight-week-old steaks taste like they were telling me all the secrets of history and steaks twice that age that were much quieter. There’s a craft to aging beef, a skill and a style. Fortunately, I knew just the guys to explain it to me.

George Faison and Marc Sarrazin are adventurers in dry-aging. They are the owners of DeBragga & Spitler, a company that’s been hanging–and aging–beef for 90 years, first in Brooklyn and later in Manhattan’s Meatpacking District.

Faison and Sarrazin take me into their massive aging room in the company’s modern facility. It’s cold, basically a refrigerator the size of a house, and the smell is beautiful: like sage, a warm stick of butter, peanuts, and blood. There are new beef loins and old loins, meat as bright as a balloon and meat as dark as coffee dying for some cream. The smell is mellow and round and all-enveloping; if it were a sound, it would be a bass line vibrating through bodies at a show. Sarrazin breathes it in, smiles, and says, “We’re not oenophiles, we’re dry-ageophiles. Your room’s got to have a clean smell. If you walk into a meat locker and smell anything sour, walk away.”

We talk by the rib racks, which are hung on posts lined with hooks, looking like a stand of beefy Christmas trees. It turns out there’s a lot of chemistry going on underneath that smell, including some sexy enzyme-on-protein action. As the meat rests, enzymes that were contained in the muscles’ cells work free and become a kind of creative wrecking crew. They break down proteins into amino acids, including the ones that make for umami, so the flavor deepens. They turn the small amounts of carbohydrates in the meat into sugars, so the taste seems sweeter. And they weaken connective tissue around protein strands, so the meat becomes more tender.

All those changes can happen so long as you give the meat some time, whether it’s in a dry-aging room like DeBragga & Spitler’s or surrounded by its juices in a vacuum-sealed plastic bag, which is what’s known as wet-aging. (Since almost all meat is held and shipped in plastic, it’s all wet-aged to some degree.)

But something special happens when you take the beef out of the bag and dry-age it. The meat starts to shrink as the water inside it works its way out; the flavors get concentrated, similar to how a reducing sauce becomes richer. As with long-aged charcuterie, friendly molds work their cheese-like mojo on the meat, introducing flavors of mushroomy Brie and even sweet-sharp Stilton. One bite of beef aged for that effect, and you’ll understand why putting blue cheese on a burger is such a classic combination. I’ve heard that the word funk, when musicians started using it, meant “good sweat,” like the sweat from sex. Dry-aging is what gives beef funk.

“Just like with making cheese or wine, this is a process of controlled decomposition,” Faison says. Since the beef isn’t salted or cured as ham or sausage would be, this is a financially risky game; there are hundreds of thousands of dollars’ worth of steaks in this locker, and plenty of ways the process could go wrong. (As far as food safety goes, scientists at the University of Wisconsin-Madison have found that when done properly, dry-aging can actually improve it.) “It’s not a sophisticated science,” Faison says, “but it’s a discipline to really look at the meat, to take care of it and adjust accordingly.”

By that, he means a few things. One is knowing how different kinds of beef change over time. Fattier, more marbled meat can withstand more extreme aging, but it also needs to age longer before the effects are noticeable. Grass-fed beef has a smaller window of effective aging; it contains different kinds of fats than grain-fed, and it doesn’t oxidize as pleasantly. (When it goes over the hill, it tastes “not like cheese, but like a dirty dishrag, and it’s revolting,” says Mark Schatzker, author of Steak: One Man’s Search for the World’s Tastiest Piece of Beef.) And you have to learn to see how the dark crust of jerky-like meat is forming around the outside as the cuts age; too fast, and the interior moisture will get locked in; too slow, and you’re potentially leaving the inner meat exposed to spoilage.

I manfully restrain a shiver while Faison and Sarrazin explain these things over the thrum of fans set all over the room. They’re huge, the kind you see cooling down 300-pound men on the sidelines at football games. Air movement is key, since it wicks away the moisture from the surface of the meat, keeping fuzzy molds at bay and helping water move from the interior. That, plus time and humidity, is pretty much everything that agers can control, so the rest is all about sight, feel, experience, and, if you want to get geeky about it, the particular blend of microflora they have camped out at their facility.

Amid the shelves of short loins, a color study of ragged triangles from red to black, Faison points to a few extra-shriveled slabs. They’ve been here for three months, destined to become porterhouses in Carlo Mirarchi’s kitchen at Blanca, the 20-plus-course tasting-menu counter in Brooklyn where diners pick the evening’s playlist from a stack of classic soul, metal, and rock LPs. Guests sit in leather captain’s chairs while eating pasta stuffed with molten pine nuts or grilled snow crab filled with sea urchin and sake lees–and pay $180 for the experience. When it comes time for the beef, though, Blanca plays it dead simple: One small slice, maybe a garnish, and just like that, Mirarchi hits you with more hot funk than anything on the record player.

Faison hauls down a rib rack; at just 30 days, it’s much less mature than Mirarchi’s, but it’s already lost 14 percent of its original weight. He asks his butcher to trim off the crust and cut it into rib eyes, and by this point, it’s lost a total of about 40 percent, which goes a long way in explaining why dry-aged beef is so expensive. It takes almost twice the original amount of meat to “make” a dry-aged steak. (Add in the cost of labor, rent, and energy it takes to age the beef, and a $7-per-pound piece of wet-aged beef now costs $15 per; double or triple that after a retail or restaurant markup.) Faison cuts us another rib eye, this one wet-aged only. The dry-aged meat is the purplish color of wine; next to it, the wet looks more like cherry soda.

Once the steaks are grilled and rested, we dive into them side-by-side to taste the difference. The wet-aged is an undeniably tasty hunk of cow. It’s a little chewy, but it sloshes with juice as I cut into it, and it has a high note, an iron-y mineral tang, mellowing into the roundness of fat–two distinct points of flavor.

Then we go at the 30-day dry-aged rib eye. I take a bite. Then I take another. Then a third, compulsively, and the flavor makes me feel a little like I might be going crazy. Does that steak actually taste like popcorn? Jamón Serrano? Bread and butter, or a soft cheese? Am I going bananas? (And no, really, I think I taste a bit of banana in there, too.) They’re insanely delicious, all these flavors that I didn’t get from the wet-aged steak. Instead of popping up one after another, they’re coiling around each other.

I notice, too, that the texture of the dry-aged steak is different. You can see that the muscle fibers are packed closer, tighter, and as you chew, they feel a little lusher, though there is no visible juice on the plate.

Despite the fact that dry-aged beef has literally lost moisture, a report for the National Cattlemen’s Beef Association suggests that many tasters think it’s juicier than wet-aged. One reason may be that with less water, you actually increase the ratio of fat in the meat, and that concentrated fat coats your palate. Another is that dry-aged muscle fibers lose the ability to hold onto moisture, and so, when you chew the meat, it’s actually releasing more juice. Because the flavors are more intense in dry-aged beef, we salivate more as we chew it–our mouths make it seem juicier.

Wagyu Strip Loin
Aged: 70 days
Cost: One slice is served as part of the $180 tasting menu at Blanca, Brooklyn

Still, not everyone is sold on dry-aged beef. In fact, in the same Beef Association report, almost twice as many people preferred wet-aged over dry. Steak juice pooling obscenely on a plate is a pretty good look, I guess. And, since very little beef is dry-aged, most steak eaters are more accustomed to the flavor of meat that comes right out of the wet-aging bag.

That familiarity is what’s driving chefs like Humm to play with dry-aged beef. “You want people to taste it, to know it,” he tells me. Which makes sense: If your life’s work isn’t just making delicious things for guests but surprising them, introducing them to something they may have never experienced, what could be more gratifying than doing it with something they think they’ve tried a million times?

For a recent five-course, all-beef dinner at New York’s Northern Spy Food Co., chef Hadley Schmitt served a midcourse shot of beef “tea” made from dry-aged rib bones, and it was one of the most astonishing things I’d ever sipped. It tasted like country ham, it tasted like pho, it tasted like shiitake, it tasted like how bad you miss your mama when you’re sick, and I stopped counting how long the flavor lasted after I got to two full minutes. When I ask Schmitt how he thought to make it, he says, basically, that he wanted to find a way to use the bones because they just smelled too good to keep to himself.

That same spirit drives Joshua Skenes of Saison in San Francisco. He may wrap a strip loin in wild grasses while drying it to impart their aroma. Or he might lightly salt it or let the salinity come from swaddling it in seaweed. “I’m not really interested in being innovative,” he says. “I just want to learn as much as I can about a product, getting it to its deepest point in flavor, and nourish people with it.”

I get where these chefs are coming from. One night, I bring home what’s left of a 28-day T-bone from old-school steakhouse Smith & Wollensky: blood, bones, and butter. The bones still have hunks of beef on them, fat caps and luxurious gristle. Later, I drop them into a pot of Rancho Gordo tarbais beans. As the gristle becomes velvety and the musky flavor of age sinks into the soup, the rich fat emulsifying into the broth, I realize that this is one of the best things I’ve ever done. I mean that morally, philosophically, aesthetically. Like, it’s up there with graduating from high school, getting engaged, and seeing the moon reflected in a hidden mountain pool in Yosemite. I bring the beans to a party that night and spoon them into friends’ bowls. “Try this, try this, try this,” I keep saying. “I’ve never tasted anything like it.” The flavor had gotten into my brain, into my bones. And like Skenes, like Schmitt, like Mirarchi, like Brisson, like Humm, I want people to taste it. To know it.

Age Overnight
Here are three meat masters who will send dry-aged beef straight from their lockers to your door.

Allen Brothers
$280 for 6 steaks
Can’t decide between porterhouse, strip, or rib eye? Don’t. Get ‘em all with a bone-in dry-aged sampler.

DeBragga
$399 for 12-14 lb.
Sure, they have steaks, but try the prime seven-rib roast, a heroic piece of meat that arrives with at least 30 days of age on it.

Pat LaFrieda
$60 for eight
6-oz. patties
This family-owned company’s legendary dry-aged burger patties are the way to go.

Francis Lam is the Editor-at-Large at Clarkson Potter, a judge on Top Chef Masters, and tweets @francis_lam. In past lives, he was a senior writer at Salon.com, a contributing editor at Gourmet (RIP), and his work has appeared in the 2006-2012 editions of Best Food Writing.